Thread-controlling mechanism for sewing machines



Aug. 3, 1943. R. BECKER 2,325,995

THREAD-CONTROLLING MECHANISM FOR SEWING MACHINES Filed Dec. 22, 1941 2 Sheets-Sheet 1 3 woe/Mob EuooLp/v Becker Aug. 3, 1943. R. BECKER 2,325,995

THREAD-GONTROLLING MECHANISM FOR SEWING MACHINES Filed Dec. 22, 1941 2 Sheets-Sheet 2 Rudolph Becker outfit Iii-aybe; readily applied to tastandardltybe Patented Aug. 3, 1943 PATENT 1 came -t; -i I y 7 2,325,995" f a V THREAWCON-TROLLINGnIECHANESM:FORs

:SEWING MAGHdNESs v Rl'idolbh'l ie'ck er, NorthlPlain fi'eltlj N. 3., assigncr to Tlie SingerManufacturi-ng camel-1y, Elizabe th; NFJJ a corporation's; Newflersey' A pplieationvbecember 22, 19il,'.SerialNo.l 423,93"

This invention: relates to sewing: machines and more particularly to controllingv mechanisms thereforzi improvedf needle -thread' In certain classes ofqWork, such-:as necktie stitching; exceptionally loose stitches are required to give the"resultantseam: theproper amount of elflSfiGity: Heretofore it has been the usual practice to performsuoh? loose stitching operations with a-sewingtmachinawhich is and-- instead so as to providezveryrlittle tension in the needle thread, therebygiving rise; to thewloosely the thread re(armaments bECQ HSEWIHUJSGY thread is needed to complete? a stitch as; the. work be.-

comes thiclger. Theabove cited threadhandling 213 difficulties are all present in regular: stitching operations using normal needle-thread tensibnsg but such difliculties all becomahighiyimagnified whenever loose? stitches; especially ofi'the' single thread ;chain-'stitch variety;- are to r be: produced with uniformity! in? a fabric-.5 It: isftherefore; an

ob' iect of the-presentinyenticn tb overcomezthe above cited stitching d-ifiicultiesbyrprovisionrof an; mproved needle 'thread controlling. mech'ay Another object I of this invention is to provide an improved needle thread'lscontrblling: mecha nism'including a" thread pull-cit device' s which I is adjustablewhereby various predetermined amounts of -needle-thread' mayfbei made available for stitching purposes; 1 1

Another object of: the" present: invention uis to provide a needle' thread pull-olfdevice wh iclmeis automatically. adjusted to com pensate' for variations in thicknesses of worlc passing. through the machine, and'whichis manually adjustable so that it may be set to 151x11 off I various f nr'edeter mined amountsof needle-thread 1' corresponding to stitch 'lengthadjustmentsnl A furtherobject of the present inventien'is to provideart-improved compact and" inexpen-v s ive needle-thread-controlling outfit. comprising thread pull-off andthreadtake-npdevices;which of'sev'ving, machine; 7

With the above and other objects in View; as

WilL hereinafter appear; the invention comprises I the devices; combinations and arrangements of parts-hereinafter set forth and:illust1'ated.in ..the accompanying drawings of. a .preferred embodillleilb 'ofl.thiLihVSIItiOD fIOm which the several features of the. inventionli and the. advantages dined thereby willbe readily understoodvby those skilled in the art. V t

In the. accompanying, rawings, Fig, 1 is Ialfront elevation. of Ta sewing machineiemboclying .the

present'inventionpj,

Fi 2"is.a1e'ft end View of the machine shown in.Fig.,.1. j Fig.3 is a portion of the removeds l l l t rizontal section takensubstam but with'fthe pull-eif arm ingits loyver position.

fieferring more specifically to the drawings,

theinven-tionisdisclosed as embodied 111 a sewing machine having a frame colnprising'a base If standard 2", andanfoverhanging 21m 3' which I terminatesirra'hollcwhead iif A-maimor'needlebar-"actuatingshaft Sis journaled; lengthwise of the rinS'and mounted atjits rear end is. a combine d belt i and hand-wheel 6i The forward end ofthe sh ft 5 actuates; by means of the crank fl andtthe link-8; a rec'ip eatery needle-bar Syvlfiibh is isuitablt' journaled: *1 l the head 4 and carries an eye=pointed needle I'O'at its lower end. Also moun'ted in "the head fii's a spring pr'essed 'presser bar l-l to the'lower-end-df whichis secured, as by a clamp-screw 2; a pi'esser-foot f3;

Cooperating with the presserdoot l3 to efiect stan by-step movements" of the workj between successive"reciprocations'of the-needle I6, is a feed-dog 4 which operates through a s'lot'l 5"in the-clothapiate l6. This' feed-dog I ids-adapted to -he given backWai'd 'andfOrWard and rising and=fallingmovements such asare common in conventional four=rnotlon feeding mechanisms. These movements :are efieeted by suitable mechanism 1 located fwith'in the? base i of themaohine.

The amplitude of feed-dog movement, which directly governs the stitch length, is" ad justedby manipulation of the usual feed adj listing lever I l projecting througha slot I 8 formedin the forward'wa'll fOf the standard 2; [Indicating means inithe foi m of mailman-petals is providedon the standard 2 for cooperation with an indicating plate 20 carried by the lever ll. Provided on the plate L) are limits or numbered lines 21 which indicate the stitch lengths to which the lever l1 may be moved to thereby govern the amplitude of the feed-dog movements. A more detailed disclosure of the present feeding mechanism may be had by reference to my U. S. Patent No. 2,222,017, dated Nov. 19, 1940.

Mounted in'the base I of the machine is a retary shaft 22 carrying upon its outer end a conventional rotary wing-type chain-stitch looptaker 23 which cooperates with the needle III in the formation of single-thread chain-stitches. Suitable mechanism within the machine frame effects rotation of the loop-taker 23 in timed relation with the reciprocations of the needle l9.

For a more complete disclosure of the present stitch-forming mechanism reference may be had to my U. S. Patent No. 2,222,016, dated Nov. 19, 1940. I

Secured to t he needle-bar 9 by means of a clamp-screw 24 is a collar 25 from which extends a bracket 26. and protruding through the slot 2? in the hollow head'4 is a thread-engagingpull-off arm 28 and a take-up member 29 containing the take-up thread eye 30. It is to be understood from the above description that collar 25, bracket 26, pulloff arm 28 and take-up member 29 all reciprocate as an integral unit with the needle-bar 9.

Secured to the presser-bar H by 'means of a clamp-screw 3| is a collar 32 from which extends the bracket-arm 33v pivotally supporting the thread-guidearm 34 by means of a pivot screw 35 and a nut 36; The free endor thread guide.

portion of the arm 34 is .U-shaped and is provided with two thread eyelets 31 disposed one on each side 'ofthe vertical plane containing the pull-oif arm 28..

Extending lupwardly' from the. threadguide Extending from the bracket 25- arm 34 is an indicatin and adjusting member or arm 38. having its free end pointed as at 39 to function as an indicator finger which is adapted to'c'ojoperate with the indicia-carrying plate 40 secured to the face-plate 4i. Mounted upon the free end portion of the member 38 is a knob 42 Y which is adapted to function as a handle so that the operator-may grasp the same and swing. the member 38 about the pivot screw 35 L to thereby adjust thethread eyelets 3'! relative torthepulloff arm 28. The friction washer 6i, disposed'between the arm-34 and the bracket-arm 33 gfricti n1a1ly retains the adjusting member 33 and the arm 34 in their, proper adjusted positions. The plate 40 is provided with limits or numbered lines 43 which correspond to those lines 2| found. on

the stitchlength indicia plate l9.

* secured thereto directly below the collar'32, the

usual. laterally extending arm 41 which is engaged by the presser-barplifterAB in the usual ma nner, as for example when the operator raises the lifter 48 for the purpose 'of elevating the 7 presser-footl3. It is to be, understood therefore;

that since the collar 32 is secured directly to the presser-bar l I, the bracket-arm, and consequent ly the thread guide 34 will be raised and lowered directly with the presser-foot it whether the foot be actuated by means of the manually controlled lifter 58 or by the action of work passing beneath said foot.

Projecting from the front of the machine arm 3 is a periodically acting thread nipper comprising a general shank'portion 69 mounted for lengthwise movement in a stationary sleeve 59 which is threaded directly into the arm 3. A coil spring 5| causes. one end of the shank ii) to engage an actuating cam 52 fixed on the shaft 5. Between a head portion 5301 the shank lit and the sleeve 5-3iare mounted two thread-engaging disks 56 which are adapted to receive the needle thread between their respective inner faces. The coil spring 5| causes the disks to normally forceably engage each other'and rotation of the cam 52 will periodically shift the shank 49 outwardly and open the disks to thereby release the thread caught therebetween.

As best disclosed in Fig. l, the needle-thread 55 is delivered from a supply source, not herein shown, directly to the usual double disk tension unit 55 from which it is threaded through the eyelets 37 of the thread guide 34, and then it is-led backwardlythrough a stationary eyelet 57 to the thread-nipper 54. From the nipper unit the thread is led forwardly through a pair of stationary eyelets 58 directly to a stationary thread guide generally designated by the numeral '59. Finally the thread is led from the guide 59 to the take-up thread eye 39 and then downwardly between the guide disks 60 to the needle Hi.

Havingthus described the details of the present needle thread controlling mechanism, the operation thereof will be understood as follows: The machine being threaded as described and power being applied to the belt-wheel 6, the needle l8 descendsto present the loop-taker 23 with a needle-thread loop in the usual manner. As the needle thus descends the cam 52, being suitably cut,.permits the nipper to remain closed andlthereby clamp the needle-thread 55. As may be best seen. .in Fig. 6, the pull-off member 28 in descending with the needle-bar 9 engages the needle thread 55 strung between the eyelets 31 of the'thread guide. 34 and thereby pulls oil a length of: thread through the tension 55' from the supply source. The closed nipper prevents any thread from being stolen from'the' needle. The length of needle thread pulledoif from the supply at any one stroke of the pull-off member 2t depends upon .the positiono-f'the thread-guide 34 relative to. the. pull-cit member. Referring to Fig. ,2 it is t'o'b'e'seen that as the thread guide 34 is elevated thepulli-o'ff arm will engage the thread strung between the'eyelets'iil for a longer period of time and thus pull off a greater length of thread from the supply. Fig.2 illustrates in solid lines, the thread-guide 34 and its control arm 38 adjusted so as to pull oii alength of thread-sufficient .to produce one stitch When the stitch length is. adjusted to e'ight'stitchesl per inch. 'Fig, 1 shows thesltitch length lever l1. correspondingly adjusted for eight stitches per-inch. Fig; 2 i11ustrates, in dotted lines, the thread guide 34 and the. stitch length lever I! adjusted to producefour stitches per inch and thus requiring a greater length of available needle-thread.

. .hereinabove described the. thread guide '34 Willbe raised and lowered directly with the presser-foot 13. It is to be understood therefore, that 'car eeramg a se sment steer-gee eie-pt dbettveeri I and sai'd' stitn sewinga frame f fie ai thread tension; thread between said spun-s arm st ining on reeeter s'aid ter'i'sion and akr rei erates Withjthe the looptaler r= beg-ms 'its nearest the 54 open and release the thread date by tl i bulll oi f niernb Ed- I wea s i in mete 41 i r a fia -e r lishin units-fer mtvements Qf' said-manually e meenani-sm stit-chthe d t b'the suite t s r fi susnysae 'of t thread 'vaila ble" by ano'ant thread phlled oil by said pull-ofi arini and a thread take-up member engaging the tenets said flipper ahdsaid needle; *ajse machine, aframe'ftermin'ating d, aneedj a r journaled'insai'd ff; arm" carried said par for pulling off predetermined lengths thread; a thread-guide" associated with w s n if "'bein g sustaihedby said From the above'itisto be an 'er'stebdj'that t to properly adjust thepresent needle-thread conggs-m t trolliingmewammfihPemtr need only Select varytlie lehgtlio'f threadnuiiedoif by Sal-spun e proper stitch length for Q at hand off arm, and nieans"carried bysa'idhoi'lowhead then set the Stitch length adjusting lever establishing limits of movements of said manuy-c nti' led mea H a the tlflread guide d i g member to ally controlled means corresponding to prede- P respfifctlve corresponding 11m1ts. termined amounts of thread pulled oiT- by said Thus it 15 to be understood that a sewing map 1l 1'-f ann chine having the present needle-thread control- In a sewing machine a frame, a needle ling mechanism is Particularly adapted for the needle-actuating means, a needle-thread engagproduction of loose stitches, in a fabric such that mg membEr, Said need1e thread engaging all of the stitches are uniform in character, parber being actuated by said needle actuating ticulairly regards the m I Slack thread means, a normally stationary thread guide assotherem. Furthermore, this machine is adapted mated with said thre'awengaging member means to provide such uniform stitches at all timS Y responsive to the variation in Work thickness to automatically adyustmg the thread pull-off action automatically adjust m d thread guide relative to as the work thickness varies and by having a Said thread engaging member, manually com I manually adjustable M m by means of which the trolled means for adjusting said thread guide rel- I the unitary threadguide and adjusting mechoperator may adjust the pull-off action to compensate for any change made in the stitch length, thereby to provide auniform amount of slack in all stitches; 6 I

n a sewing machine, a frame, a needle-bar, With particular reference to the accompanying, a pressebbar a ,threawengaging member, Said drawings it is to be understood that the present thread -engag1ng member belng actuated by said needle thread controlllng outfit, comprising the 0 me 8 d1 e bar, a thread ide associated with Said umtmy pun-Off member and take-up and thread-engaging member and having a plurality i I o opera ive positions, said thread-guide being iggi g fi 3 2 25 11 2? g gg gflggigz f gjf gfi carried by said presser-bar, manually controlled more, such an outfit may readily be applied to a means carned.by Sam Presser-Par for adjusting standard sewing machine Without involving any said thread-guide relative to said thread-engagmajor changes in the normal machine structure. t may be observed that the entire outfit, including both of the above noted unitary structures,

ative to saidthread-engaging member, and indicia carried by said frame in cooperative relationship with said manually controlled means.

and disposed in; cooperating relationship with said manually controlled means.

contriilled means correspondingtopredetermined 7 ing member, and 'indicia carried by said frame is supported by the Wessex and needlwbars. 7. In a sewlng machine, a frame terminating Having thus set forth the nature of the inhollow head, a e-bar and a presser-bar vention what I claim herein is: Journaled in SaidhollOW head, a thread D -01f 1 5 sewing machine, a need1e bar, a thread member carried by said needle-bar for pulling ll ff member, a thread takeqlp member, Said ofi predetermined lengths of needle-thread, a thread n fi and Said takemp members being thread guide associated with said pull-01f memactuated by saidneedle-bar, and a thread-nipper and C ried by said D esser-bar, manually for engaging the needle-thread between said controlled means including an arm member ex- 11 and Said tgk m tending from said thread guide for adjusting In a sewing machine, a needle-bar, a thread Said thread guide a e o Sa D -Off mempu1l-off member for pulling off predetermined 7 and indicia carried by said hollowhead and lengths of needle-thread, a t d take-up m associated with said manually controlled means. her, said pull-off and said take-up members being 3. In a sewing 'machine, a V hollow head, a actuated by said needle-bar, manually controlled needle-bar journaled in said hollow head, a means for varying the amount of needle-thread bracket-arm carried by said needle-bar, a pullpuiled off by said pull-ofi' member, and a periodioff member for pulling off predetermined lengths with said thread guide for adjusting the same.

relative to the pull-off memberdand means carried by said hollow head for establishing limits of movements of said manually controlled arm.

9. In a sewing machine having aframe including a hollow head portion, stitchingmechanism including needle-actuating mechanism,

' feeding mechanism, means't o adjust the stitch length including a manually controlled lever and cooperating stitch .length indicating means, a

needle-thread pull-off member for pulling off predetermined lengths of needle thread, said pull-off member being actuated by said needlewith said pull-off member, and apresser-bar; the improvement which consists in the provision of adjusting means carried by said presser-bar and associated with said thread guide for shifting actuating mechanism, a thread guide associated 20 the same relative to said pull-off member, and 5 indicia carried bylsaid frame and associated with said adjusting means for establishing limits of,

movement of said means corresponding to those of said stitchlength indicating means.

., 10. A thread-controlling device adapted for attachment to a sewing machine, having a hollow head, and a needleand a presser-bar mounted within'said hollow head, said threadcontrolling device comprising, a thread-engaging arm adapted to be secured to said needlebar, a bracket-arm adapted to be secured to said presser-bar, a thread-guide complemental to said thread-engaging arm, and a manually controllable arm associated with said thread-guide, said thread-guide and said manually controllable arm being adjustably carried upon said bracketarm.

11. A thread-controlling device adapted for attachment to a sewing machine having a hollow head and a needle and a presser-bar mounted within said hollow head, said thread-controlling device comprising, a bracket adapted to be secured to said needle-bar, a pull-off armand a take-up member extending from said bracket, a-

bracket-arm adapted to be secured to said presser-bar, a thread-guide complemental to said pull-off arm and adjustably carried by said bracket-arm, and an adjusting member carried by said bracket-arm for adjusting said threadguide relative to said pull-off arm.

' RUDOLPH BECKER. 

